Help Choosing a Carb for a chevy 350

[Maniak]

I have a 1983 Chevy 1 Ton Flatbed that needs a new carb.

It currently has some unknown, falling apart, really bad shape edelbrock carb.

The truck has a 350 motor with a 4 speed transmission (its has granny and then 3 more gears) with no OD.
Rear end Ratio is 4:11
Tires are 31.7" tall (235x85xr16)

I was thinking of a Edelbrock 1406 Carburator which is I belive a 600CFM carb set to be lean to help with mileage

I want as good as mileage as I can get (I only drive at 60-65mph) but I need to be able to tow the explorer to the trails so I still need decent power and everywhere is freeway driving to get to.

At 65 mph my math tells me the truck will be turning 2800 rpms (Is that ok for a 350 ci motor?)

Also, If the wells go dry again, I will be carrying about 6000 lbs of water on the back of the truck (not flat ground).

If anyone has any ideas as to what I need, please let me know.. I "think" stock the truck came with a 700cfm quadrajunk and I think a 500cfm won't be enough for that motor when I cruise down the freeway (or go up the hills).

Oh yea.. I was thinking edelbrock since the carbs are all < $300 and money is an issue.


~Mark

 

[JDraper]

IMHO, stay away from the Edelbrock carbs. I've never had good luck using them. I'd go with a Holley Truck Avenger carb. I run the Street Avenger version and it is an excellent carb for the $$$. Between 600-700 cfm should be good. The Truck Avenger is a vacuum secondary 4bbl, so it'll give decent mileage too. Check out http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY-0-90670&N=700+115&autoview=sku .

 

[aldive]

IMHO, stay away from the Edelbrock carbs. I've never had good luck using them. I'd go with a Holley Truck Avenger carb. I run the Street Avenger version and it is an excellent carb for the $$$. Between 600-700 cfm should be good. The Truck Avenger is a vacuum secondary 4bbl, so it'll give decent mileage too. Check out http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY-0-90670&N=700+115&autoview=sku .

I second the recommendation by Jeff.

 

[JDraper]

FYI, here are a couple of CFM calculators to play with:

http://www.wallaceracing.com/intakecfm.php

http://www.4secondsflat.com/Carb_CFM_Calculator.html

 

[Maniak]

Is there another model close to the one listed above that is tuned more for mileage? I already know i'm not going anywhere fast so I don't need all the power I can get.. but Gas makes me have to pick/choose when/where I go wheeling.

I don't "need" the rough terrain fuel control, etc.. and its a good $120 more than the 1406.. Is it really worth the price difference (I only know Edelbrock becuase I couldn't use a Holley on the van since it wouldn't physicall fit in the dog house).

~Mark

 

[JDraper]

Holley 4160

Take a look at that. 600 CFM Vacuum secondaries, $275.00

 

[JDraper]

One thing to make sure of is whether you have a square or spread bore manifold...the standard manifold has all four bolts in a square, the spread bore has two bolts spread further apart. I know that Chevy occasionally used a spread bore setup.



EDIT!!! I just noticed your truck came with a Quadrajet stock...that's a spread bore carb. Either you need to get another spread bore, or switch to a square bore intake manifold.

 

[Maniak]

Thats more in my price range...

Looks like I'm going to buy the 1406, unless another, better idea comes up from you guys... I have another 2 weeks before I'll order it (I'll be out of town).

Stupid question.. anyone venture to guesse what "normal" gas mileage will be for the truck at 65mph or so, unloaded on flat freeway?

I was getting 10 ish with the bad edelbrock (smelled rich at idle and when running even with the mixture screws turned in) with no load.

~Mark

 

[Maniak]

My truck has a spread bore intake, but it already has an adapter plate on it for the squre bore edelbrock.

Is that bad? Should I be looking for a spread bore carb?

~Mark

 

[JDraper]

My truck has a spread bore intake, but it already has an adapter plate on it for the squre bore edelbrock.

Is that bad? Should I be looking for a spread bore carb?

~Mark

Since you already have the adapter, you'll be ok. A spread bore carb will run you a lot more $$$

 

[Maniak]

Well.. Its time to buy the carb.. I found a bunch on ebay.. Here are 2 that I found that seem right..

How's this one look?
http://cgi.ebay.com/ebaymotors/HOLL...9QQihZ016QQcategoryZ33550QQrdZ1QQcmdZViewItem

Or this one?
http://cgi.ebay.com/ebaymotors/Holl...5QQihZ020QQcategoryZ33550QQrdZ1QQcmdZViewItem

I can't tell the difference so I can't tell which one to get, or does it even matter?

Thanks

~Mark

 

[JDraper]

They are the same carburetor in both auctions. The 4160 is a good carb and should work well for ya.

 

[james t]

Dude, keep the Eddie and rebuild it. Its the simplest carb ever. Its super easy to rebuild, super easy to tune, and it stays tuned unlike a Holley *cough im sorry Jeff cough* :

If you have never rebuilt a carb then buy a rebuild kit for your Eddie and get after it. You can do one in less than an hour with no carb experience whatsoever. Im sorry i think Holley is one of the best street car power carbs but they suck as a "leave it alone" truck carb. If its a one ton flatbed then it wont see wild offroad use anyway.



and BTW- the Qjet is one of the best truck carbs ever made period. You cannot get better fuel mileage than a Qjet and they make good power too. They also work like EFI offroad except for elevation changes. You just have to be a voodoo witch doctor to tune one.

 

[JDraper]

Edelbrock...yuck :

I've never had any good luck with their carbs (their other products are pretty damn good)...couldn't ever get them tuned right no matter what was done. Some people swear by 'em, some hate 'em...They definitely are easier to rebuild and IF you do get one tuned correctly, they hold a tune better than the standard Holley's do. That's one reason I originally recommended the Street or Truck Avenger. They come ready to run out of the box, and hold their tune well. Holley took some cues from the aftermarket and re-designed the needle valve area and put blowout protection valves in from the factory. Yep, they cost more, but work REALLY well...

Maniak, if your truck ran well before with the Edelbrock, and it's just gone downhill over time, I would also suggest trying a re-build before buying a new carb. If it's always run like crap with the Edelbrock, I'd go for a Holley.

 

[james t]

Honestly just take the adapter off and get a Qjet for it from Summit or Jegs. They can sell you one ready to bolt on out of the box and you will not get better economy out of ANY other carb out there, 2 barrels included. If you start with a new one that is right from the begining then you cant beat a Qjet.

 

[Maniak]

When Q-jet was long gone before the previous owner got the truck.. From what I understand, there was an engine fire (I can still see some remenants from it) 2 owners ago and the carb wasn't salvagable.

The Edelbrock was put on by the PO, but it was already a heavily used, rebuilt unit. I took another look at it and I don't think it is salvagable. The shaft wobbles in the bore now and the 2ndaries bind up enough to make it a pain to step on the gas lightly. The issue seems to be the metal cams(not sure what you call them) that keep the 2ndaries from opening at light throttle. I bent the cams away from each other a bit (so less metal is rubbing) and it is easier to push on the gas, but this carb just seems not worth it to use..

Also, with it leaned all the way out I'm still getting black smoke (really rich).

The truck should never see off-road (maybe dirt road etc on the way to a trail). It will be used to pull the explorer to the trail (trailer), which means It will be on the freeway (65mph max). If the wells go dry again, it will be used to carry about 5600lbs of water (700 gallon water tank) about once a week. It will be all 2 lane hilly so I won't be going fast then either. Heck, dually with 4:10 gears and no o/d with 31" tires (285x70r16 I think) really spins the motor.

~Mark